Recent advances have led to the appreciation that Pathogen-associated Molecular Patterns (PAMPs) derived from microbial pathogens have adjuvant activities. A major conceptual advance in innate immunity has been the discovery of Pattern Recognition Receptors (PRR) that recognize these PAMPs. This recognition profoundly shapes adaptive immunity, thereby impacting host responses to pathogens and to vaccines. A plethora of PRR families have now been described. While some PAMPs are known to activate a specific receptor, more in-depth analyses have revealed that many PAMPs activate multiple PRRs or PRR pathways. The overarching purpose of this project is to use a novel nanoparticle (NP) platform to deliver PAMPs that can best activate the innate immune system to shape the desirable adaptive immunity for beneficial, efficacious vaccine outcome. The distinguishing technology platform of this application is the production of NP by a soft lithography particle molding process called Particle Replication In Nonwetting Templates (PRINT), a technology described and further studied in Project 1. A major advantage of PRINT is the fabrication of large quantities of immunologically-inert NPs of precise size, chemistry, porosity and shape of Good Manufacturing Practices (GMP) quality. This proposal plans to co-deliver antigen and PAM adjuvant complexes by PRINT-NP to optimize vaccine responses. This platform of vaccine/adjuvant delivery by NP will be used to test vaccines against viral pathogens of high medical needs. Mechanistic studies are also proposed to understand how the PAMP adjuvants activate the immune system by defining the specific receptors that mediate the effect of a PAMP adjuvant(s). Challenge studies will be performed in appropriate large or larger animal models to enable eventual translation to the clinic.